There is known a technique (e.g., Patent Document 1 mentioned below) for displaying on a monitor a picture obtained by viewing a virtual space from a viewpoint in a viewing direction, the virtual space being created in a computer, where a plurality of images are placed according to the mutual relevance thereof and the viewpoint moves in the virtual space according to a user operation. According to this technique, the user can find their desired image by moving the viewpoint to thereby update the display on the monitor.    Patent Document 1: Japanese Patent Laid-open Publication No. 2004-30122